Refrigerating apparatus



Dec, 5, H939. J. W. CRAIG REFRIGERATING APPARATUS Filed Feb. 28, 1958 u U00 U00 6 UU af/w. U00 o 0 g5 6 i H H I/ 'l HW H H/ H m I H HM I Ivf HM U /H m .uw @HW H 7 H/ H r HM u UOUU H u UU HW u U H/ u 000 l. u fi Q n.. uw W 0 6% N VENT OR ATTORNEYS Patented Dec. 5, 1939 UNITED STATES 2,1sa31z nEFarGEnA'rmG APPARATUS John W. Craig, Dayton, Ohio, assignor to General Motors Corporation, lDayton, Ohio, a corporation of Delaware Application February Z8, 1938, Serial No. 192,991 I 6 Claims.

This invention' relates to refrigerating apparatus and more particularly to intermittent absorption apparatus employing a re-absorber instead of the usual evaporator.

It has been found'that the efiiciencyof intermittent absorption refrigerating systems can be er during the generating cycle.

l'temperature generator absorber.

increased if instead ofthe usual evaporator, a second generator absorber is' used which liberates the refrigerant at a comparatively loW temperature. In such systems it is customary to provide a secondary refrigerant system in heat exchange relation with the low temperature generator absorber for dissipating the heat of association in the low temperature generator absorby With many installations it has been rather difficult to provide a simple scheme for such a system, since some means must be provided 'for conducting the liquid, which is liquefied in the condenser of the secondary system to thecooling unit or the low lIt is an object of my invention to provide an improved means particularly adaptable to household refrigerators for returning this condensed liquid in the secondary system to the cooling unit.

It is another object of my invention to provide an improved intermittent absorption refrigerating system employing a re-absorber as a cooling unit in which substantially the entire mechanism may be placed below the cooling unit.

It is still another object of my invention to provide a heat pump operatedby the burner, which is also used to heat the high temperature generator-absorber, for pumping the liquid from the condenser in the secondary system to the cooling unit.

Further objects and advantages of the present invention will be apparent from the following description, reference being h'ad to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

'The figure is a diagrammatic illustration of a household refrigerator cabinet provided with an intermittent absorption refrigerating machine employing a low temperature reabsorber as a cooling unit.

Briefly I have provided an. intermittent absorption system for a household refrigerating system in which the cooling unit forms a part of a secondary refrigerant system connected to a condenser in the machinecompartment and a liquid pump heated by the burner of the high temperature generator-absorber is provided for pumping the liquid from the condenser up to the cooling unit.

Referring now to the drawing there is shown a domestic refrigerator cabinet 20 provided with a food storage compartment 22 and a machine compartment 24 located beneath the food storage compartment. The machine compartment contains a generator-absorber 26 connected by a refrigerant conduit 28 with an inter-lock control means 30 which in turn is connected by a refrigerant conduit 32 with a pressure controlled valve means 34 which provides substantially no resistance to the ow of refrigerant driven off from the generator-absorber 26 to the refrigerant conduit 36 which connects to a low temperature generator-absorber 38 located within an insulated compartment 40 of the cooling unit 42.

The cooling unit 42 is provided with ice tray compartments 44 which are surrounded by refrigerant ducts 46 which depend fromthe insulated compartment 48 which contains a secondary heat transfer liquid 48 in the form of a bath in which is supported the low temperature generator-absorber 38. The insulated compartment 40 containing the secondary refrigerant liquid 48 is provided at its upper portion with a Avapor conduit 50 which extends through the rear wall of the cabinet and thence down the back wall of the cabinet to a tube and fin type condenser 52 where the evaporated secondary refrigerant may be condensed.

I'he condenser 52 drains through a conduit into a heat operated liquid pump 56 provided with a check valve 54. 'I'he liquid pump 56 is located over one end of the burner 58 so that it is heated during any operation of the burner. This heat causes the liquid to be forced upwardly through the liquid conduit 60 by means of the vapor pressure created in the chamber of the liquid pump 56 by the heat from the burner 58. This conduit 68 is provided with ns along the back Wall of the cabinet for cooling the liquid before it is discharged within the insulated chamber 40 over the surfaces of the low temperature generator-absorber 38. In this way the evaporated refrigerant is condensed and then returned to the cooling unit during each operating period of the burner 58.

'I'he burner 58 is provided with a pilot light 62 and the burner, but not the pilot light, is suppliedvwith gas through conduit 64 under the control of a snap acting valve 66. The generatorabsorber 26 is provided with a volatile liquid vapor heating and cooling system which includes a jacket 68 which surrounds the generator-ablil lll

bustion from the burner 58 in order to assure uniform heating of the generator-absorber 26.

The upper portion of this jacket 68 is connected.

by a vapor conduit 'I0 to a pressure operated valve 12 which controls the iiow of vapor to a n and tube type condenser 16 located above the generator-absorber. The bottom of the condenser F6 is connected by a liquid drain conduit 16 with the bottom of the jacket 68. The pressure operated valve l2 is employed to operate the snap acting gas valve 66 and they are connected by a lever 88 provided with a snap acting mechanism k82, and a latch mechanism 86 which forms a part of the inter-lock 38.

As shown in thedrawing the system is shown lin'the midst of the absorption cycle. The gas erator-absorber 38.

valve 66 is closed 'and the valve 72 is open permitting the volatile` liquid in the jacket 68 surrounding the generator-absorber 26 to vaporize and pass through the valve 'l2 to be condensed in the condenser 66 from which the condensed volatile liquid may drain back to the jacket 68. In this way the generator-absorber is cooled and under such conditions the vapor pressure in the conduits 28 and 32 will be reduced to such a low pressure that refrigerant will bev drawn through the valve 36 from the conduit 36 which connects to the low temperature generatorabsorber 38.

This lowers the vapor pressure at the low temperature generator-absorber 38 causing the disassociation of the refrigerant from the absorbent therein. This is an endothermic reaction and requires the addition of heat to permit it to continue. This heat is removed or taken from the liquidand vapor in the secondary refrigerant system which in turn through the medium of the'depending ducts 46 removes heat from the water in ice trays which may be placed Within the ice tray compartments 64 and also from the air within the food storage compartment 22.

A spring 86 acts upon the lever 80 to tend' to close the valve 'I2 and to open the gas valve 66. This, however, is prevented by the latch 86 of the inter-lock 38 until such time as the generatorabsorber 26 fails to maintain a sufliciently low pressure within the conduits 28 and 32 to provide refrigeration at the cooling unit. When this limit is reached the pressure within the interlock becomes sufliciently great to move the latch member 84 downwardly to release the lever 88 and allow the spring 86 to overcome the snap acting mechanism 84 and to move the gas valve 66 to open position as Well as to move the vapor valve 12 to closed`position.

This stops the absorption cycle and beginsa new generator cycle. The gas ilow through the opening valve 68 to the .gas burner 58 which heats the volatile liquid in jacket 68 to heat the generator-absorber 26. This drives the refrigerant from the generator-absorber 26 through the conduits 28, 32 and 36 to the low temperature gen- Here the low temperature generator-absorber absorbs the refrigerant only by the evolution of heat which causes the secondary refrigerant 48 to boil and causes the vapor to pass through the conduit 58 downwardly to `the condenser 52 where it is condensed and drains into the liquid pumpk 56. Since the burner 58 is in operation liquid will be pumped upwardly through the conduit 68 and cooled by the fins charges over the warm low temperature generator-absorber 38.

As absorbents I prefer to employ manganese" chloride in the high temperature absorber and barium chloride in the low temperature absorber 38 with ammonia as the refrigerant. The use of these absorbents permit the air cooling of the low temperature absorber 38 during the generating cycle and the air cooling of the generatorabsorber 36 during the absorption cycle, even during the warmest weather normally encountered. The secondary circuit may contain any suitable volatile liquid which does not congeal but acts as described above, such as sulphur dioxide `or diluorodichloro methane.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What-is claimed is as follows:

1. Refrigerating apparatus including a. generator-absorber, a cooling unit, a secondary refrigerant system in heat exchange relation with said cooling unit, said secondary refrigerant system having condensing means located below said cooling unit, pumping means for pumping liquid collected in a lower portion of said secondary system up to said cooling unit, and heating means for heating the generator-absorber and also for operating. said pumping means.

2. Refrigerating apparatus including a generator-absorber, a cooling unit, a secondary refrigerant system in heat exchange relation with said cooling unit, said secondary refrigerant system having condensing means located below said cooling unit and pumping means for pumping liquid collected in a lower portion of said secondary system up to said cooling unit, said cooling unit including a second generator-absorber connected by conduit means with said first mentioned generator absorber.

3. Refrigerating apparatus including a generator-absorber, a cooling unit, a secondary refrigerant system in heat exchange relation with said cooling unit, said secondary refrigerant system having condensing means located below said cooling unit and pumping means for pumping liquid collected in a lower portion of 4 said secondary system up to said cooling unit, said cooling unit including a. second generator-absorber connected by conduit means with said first mentioned generator-absorber, said pumping means being operated by the heating means for the first mentioned generator-absorber.

erator-absorber, a cooling unit, a secondary refrigerant system in heat exchange relation with said cooling unit, said secondary refrigerant systemhaving condensing means located below said cooling unitv and pumping means for pumping liquid collected in a lower portion of said secondary system up to said cooling unit, said cooling unit including a second generator-absorber connected by conduit means with said first mentioned generator-absorber, said pumping means being operated by the heating means for the first mentioned generator-absorber, said rst mentioned generator-absorber containing a high temperature absorbent and said second generator-absorber containing a lower temperature absorbent.

5. Refrigerating apparatus including a. generating means, a secondary refrigerant circuit having a condensing portion and an evaporating portion, said evaporating portion being located above said condensing portion, said secondary circuit being provided with pumping means for lifting liquid from the level of said condensing portion to the level of said evaporating portion, and a heating means for heating said generating means and for operating said pumping means.

6. Refrigerating apparatus including a generator-absorber; a cooling unit, a secondary refrigerant system in heat exchange relation with said cooling unit, said secondary refrigerant system having condensing means located below said cooling unit, pumping means for pumping liquid collected in a lower portion of said secondary system up to said cooling unit, and means for intermittently heating said generator-absorber and said pumping means.

JOHN W. CRAIG. 

